Door assembly, in particular for a helicopter, provided with an emergency release device

ABSTRACT

A door assembly, in particular for a helicopter, has a post; a door fitted to the post by a first and second hinge arranged on an outer wall of the post, so as to rotate about a hinge axis to open and close a door opening; and an emergency release device having a release handle, and a stem which extends through the post along a release axis substantially perpendicular to the hinge axis, rotates axially, in response to operation of the release handle, from a first to a second angular position to detach the door from the post, and is fixed at one axial end to the first hinge; the release handle being connected to the stem to rotate together with the stem about its release axis.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of European Patent Application No.10425325.7, filed on Oct. 6, 2010, which is hereby incorporated hereinby reference in its entirety.

BACKGROUND OF THE INVENTION

As is known, aircraft must be equipped with emergency exits to allowoccupants to exit quickly in the event, for example, of a crash. Theordinary service exits on the aircraft are also sometimes used asemergency exits; in which case, the service exit door is equipped withan emergency release device, in addition to the normal opening handle.In known solutions, the emergency release device comprises a releasehandle fitted to a post, to which the door is hinged by means of twohinges. When operated, the handle, by means of rods and/or levers, actssimultaneously on the two hinges to move the two hinge seats, unseat thehinge pins, and so detach the door from the post to free the dooropening. One solution of this type is described, for example, in U.S.Pat. No. 3,851,845, which corresponds to the preamble of claim 1.

A similar solution is described in U.S. Pat. No. 4,102,011, in which theemergency release device is fitted to the door, and acts on tworetaining pins fitted to respective hinges to hold the hinges on thedoor. When the release handle is operated, the retaining pins withdrawsimultaneously inwards of the door, which is thus detached from thehinges and can be expelled from the door opening.

The above known solutions are unsatisfactory, on account of the bulk andweight of the emergency release device, which features rods and/orlevers to act simultaneously on two vertically spaced hinges. Moreover,in solutions such as the one described in U.S. Pat. No. 4,102,011, theweight of the emergency release device, and the fact that it is actuallyfitted to the door, make the door more difficult to expel.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a door assembly, inparticular for a helicopter, which is provided with an emergency releasedevice, is designed to provide a cheap, simple solution to the abovedrawbacks, preferably comprises a door that moves automatically awayfrom the door opening when the device is operated, and/or features asystem for accurately adjusting the position of the door at the assemblystage.

According to the present invention, there is provided a door assembly,in particular for a helicopter, provided with an emergency releasedevice, as defined in claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred, non-limiting embodiment of the present invention will bedescribed by way of example with reference to the accompanying drawings,in which:

FIG. 1 shows a partial external side view of a preferred embodiment ofthe door assembly, in particular for a helicopter, provided with anemergency release device, according to the present invention;

FIGS. 2 and 3 show two larger-scale details of FIG. 1;

FIG. 4 shows a larger-scale view in perspective of an inner portion ofthe FIG. 1 door assembly;

FIG. 5 shows a larger-scale, partly sectioned view in perspective of theemergency release device of the FIG. 1 door assembly;

FIG. 6 shows an exploded view in perspective of FIG. 5;

FIG. 7 shows an exploded view in perspective of other component parts ofthe FIG. 1 door assembly;

FIGS. 8 and 9 show larger-scale details of emergency release of the FIG.1 door assembly.

DETAILED DESCRIPTION OF THE INVENTION

Number 1 in FIG. 1 indicates a door assembly of a helicopter cabin 2(shown partly). Door assembly 1 comprises a door opening 3 defined by aframe 4 forming part of the outer structure of cabin 2, and comprising atop cross member 5, a front post 6, a rear post 7, and a sill (visiblein FIG. 4).

Door assembly 1 comprises a door 8 which rotates about a hinge axis 9between an open position permitting access to the interior through dooropening 3, and a closed position, in which the perimeter of door 8engages frame 4 to seal door opening 3. Door 8 is locked in the closedposition by a mechanism comprising a substantially vertical top latch11, and a substantially horizontal bottom latch 12. When the mechanismis activated, latch 11 engages a retaining seat 13 formed between crossmember 5 and post 7; and latch 12 engages a retaining seat 14 formed inpost 7 and, as shown in FIG. 3, bounded at the bottom by a ramp 18,which slopes downwards from the bottom of seat 14 to door opening 3.

With reference to FIG. 1, an outer handle 20 and an inner handle (notshown) provide for opening the door normally, i.e. releasing latches 11,12 from respective seats 13, 14 to open door 8 outwards.

Door 8 comprises a front portion 25 hinged to post 6 by two hinges 27,28 spaced vertically apart on the outside of door assembly 1.

Hinge 27 is the top hinge and comprises two fastening bodies 29, 30fitted in fixed positions to an outer wall 31 of post 6 and to an outerwall 32 of portion 25 respectively. More specifically, body 29 is fixedstably and adjustably to post 6 by a connecting assembly 34 described indetail below with reference to FIG. 7.

As shown in FIGS. 7 and 8, body 29 defines a hinge seat 35 engaged by anaxially-rotating hinge pin 36 fixed to body 30 by an arm 37. Hinge pin36 projects upwards from arm 37 along hinge axis 9, and is free to dropout of hinge seat 35, which means more or less the entire weight of door8 is supported by hinge 28. In an alternative embodiment (not shown),hinge pin 36 may extend axially downwards and be fixed to frame 4, overa corresponding hinge seat fixed to door 8 and free to fall away fromhinge pin 36.

As shown in FIGS. 5 and 6, hinge 28 is the bottom hinge and comprisestwo fastening bodies 39, 40 with a pin and seat (not shown) hingedstably to one another and coaxial with hinge pin 36 and hinge seat 35.Body 40 is fixed to wall 32, and body 39 has a base 41 resting on wall31, possibly with the interposition of shims (not shown).

Body 39 is fixed releasably and adjustably to the post by a connectingassembly 42 comprising a stem 44, which extends through post 6 along asubstantially horizontal axis 45 perpendicular to hinge axis 9, and isfixed axially along, but rotates about, axis 45 with respect to post 6.Assembly 42 also comprises a shank 46 which is coaxial with stem 44, isfixed with respect to fastening body 39, projects with respect to base41 through a hole 47 in wall 31, and is connected releasably and inaxially fixed manner to one end 43 of stem 44. Shank 46 is releasedaxially from end 43 when stem 44 is rotated from a first to a secondangular position about axis 45. Stem 44 is conveniently axially hollow,and houses a coaxial spring 48 loaded to exert elastic axial pressure todetach shank 46 from end 43 when stem 44 reaches the second angularposition. End 43 and shank 46 are preferably connected releasably by ascrew-nut screw coupling 49.

Stem 44 and spring 48 form part of an emergency release device 50comprising a release handle 51, which is connected to the opposite end52 of stem 44 from end 43, so as to rotate together with stem 44 aboutaxis 45. Handle 51 also rotates, with respect to stem 44 and about anaxis 53 perpendicular to axis 45, between an extracted position, inwhich handle 51 and stem 44 are free to rotate between the first andsecond angular position, and a lowered position, in which the tip 56 ofhandle 51 engages a seat in a fork 55 (shown partly in FIG. 4) fixedwith respect to post 6 and which prevents handle 51, and therefore stem44, from rotating about axis 45.

Assembly 42 also comprises a sleeve 58 which is fixed to post 6 in amanner not shown in detail, has an axis parallel to axis 45, comprisesan intermediate cylindrical portion 59 housed in post 6, and terminatesaxially, towards hinge 28, with an annular locating portion 61 engaginghole 47 and resting against wall 31. In the opposite axial direction,sleeve 58 terminates with a flange 60 on the outside of post 6.

Assembly 42 comprises a positioning device 57 which connects stem 44 toportion 59 to permit translation of the position of axis 45 and soadjust the position of body 39 when assembling door 8. Device 57comprises two eccentric, rotary bushings 62, 63 nested one inside theother. That is, bushing 62 has an outer cylindrical surface 64 thatmates in rotary manner with an inner cylindrical surface of portion 59;and an inner cylindrical surface 65 eccentric with respect to surface64. And bushing 63 has an outer cylindrical surface 66 that mates inrotary manner with surface 65; and an inner cylindrical surface 67eccentric with respect to surfaces 66, 65, and which mates in rotarymanner with an outer cylindrical surface of stem 44.

Bushing 62 terminates axially with a flange 71 that rests axiallyagainst flange 60; and bushing 63 terminates axially with a flange 72that rests axially against flange 71. Flanges 60, 71, 72 thus form axialsupports between bushings 62 and 63, and between bushing 62 and sleeve58, and have respective notches 73 which mesh to prevent rotation ofbushings 62, 63, and in particular define a number of predeterminedangular stop positions.

Assembly 42 also comprises a ring nut 77, which screws to a portion 78of stem 44, between bushing 63 and end 52, and rests axially againstflange 72. Ring nut 77 keeps flanges 60, 71, 72 gripped axiallytogether, and base 41 pressed against wall 31 when stem 44 is in thefirst angular position. i.e. fixed to body 39. A cotter pin or dowel(not shown) prevents unscrewing of ring nut 77, which therefore rotatestogether with stem 44, and slides against flange 72 when handle 51 isrotated from the first to the second angular position.

With reference to FIG. 7, assembly 34 comprises the same component partsas assembly 42, which are therefore indicated using the same referencenumbers as in FIG. 6, followed by the letter “a”.

Unlike assembly 42, stem 44 a of assembly 34 is solid, as opposed tohollow, and is fixed stably, as opposed to releasably, by its end 43 ato body 29. Assembly 34 comprises a bracket 79 located axially betweenring nut 77 a and flange 72 a, and which has a slot (not shown) engagedin angularly fixed manner by a portion 78 a of stem 44 a, and can slideon portion 78 a in a radial direction 80 defined by the slot. Bracket 79comprises an appendix 82, which engages a slot 83 in flange 60 a, so asto slide in a direction 84. Directions 80, 84 are crosswise to eachother, and lie in a plane perpendicular to axis 45 a, so that bracket 79locks body 29 angularly, and guides translation of axis 45 a of stem 44a during adjustment.

With reference to FIG. 4, door 8 is held in the open position by aspring 85 comprising telescopic members 86, 87. More specifically,spring 85 is a gas spring connected at the ends by pivot joints to theinner wall of frame 4 and to the inner face of door 8, e.g. at a bottomportion of portion 25. When door 8 is in the closed position, spring 85extends substantially vertically, and is compressed.

As stated, door opening 3 may be used as an emergency exit by detachingand expelling door 8 by means of device 50, despite latches 11, 12locked inside seats 13, 14. Device 50 operates as follows: after tip 56of handle 51 has been released from fork 55, when handle 51 is operatedstem 44 rotates (anticlockwise in FIGS. 4 and 5) from the first to thesecond angular position and, in so doing, is not only released axiallyfrom shank 46, but also produces axial thrust to expel shank 46, bymeans of screw-nut screw connection 49. Once detached from end 43, shank46 is also expelled by axial thrust produced by spring 48, which pushesshank 46 completely out of hole 47 (FIG. 9).

At this point, hinge 28 is detached from post 6, the weight of door 8,combined with the downward thrust exerted by spring 85, causes door 8 todrop, and nothing acts as a stop to prevent door 8 from falling. Infact, as door 8 drops:

-   -   members 86, 87 of spring 85 separate;    -   latch 11 drops freely out of seat 3;    -   hinge pin 36 withdraws freely from hinge seat 35 (FIG. 8); and    -   ramp 18 allows the end of latch 12 to slide out of seat 14 in        door opening 3.

Once detached from frame 4 by device 50, door 8 therefore dropsautomatically to the ground to free door opening 3.

As stated, to adjust hinges 27, 28, axes 45 and 45 a can be translatedinside sleeves 58 and 58 a when assembling door 8, to adjust theposition and orientation of hinge axis 9 and so centre door 8 correctlyinside door opening 3.

The procedure is the same for both assemblies 34 and 42, so is onlydescribed relative to assembly 42. After releasing and loosening ringnut 77 to slacken bushes 62, 63 axially, flanges 71 and 72 part todisengage notches 73. Bushing 62 is rotated inside sleeve 58, andbushing 63 is rotated inside bushing 62 to position stem 44, andtherefore body 39, as required.

Once hinge 28 is positioned, flanges 72, 71 are pushed axially togetherand against flange 60 to engage notches 73 and prevent rotation ofbushings 62, 63; and ring nut 77 is screwed back down to lock the setposition.

Door assembly 1 therefore needs no rods or levers to detach door 8 frompost 6, by virtue of handle 51 rotating together with stem 44, so doorassembly 1 as a whole, and door 8 specifically, are relativelylightweight.

Moreover, by virtue of the design of hinge 27, only hinge 28 need bedetached, which means only one device 50, i.e. one handle 51, isrequired, and emergency release can be effected quickly andone-handedly.

Using device 50, hinge 27 is detached completely from post 6 withoutseparating the pin from the hinge seat, and therefore moving away fromthe post 6 is relatively quick and effective.

Assemblies 42 and 34 also provide for adjusting the position of hinges27, 28 easily, without having to remove hinges 27, 28 completely frompost 6.

Other advantages will be clear from the characteristics described aboveand/or claimed.

Clearly, changes may be made to door assembly 1 as described andillustrated herein without, however, departing from the scope of thepresent invention as defined in the accompanying claims.

In particular, hinge 27 and assembly 34 may be substantially identicalto hinge 28 and assembly 42, so two release handles may be provided, onefor each hinge 27, 28.

A different releasable connection, e.g. a bayonet connection, may besubstituted for screw-nut screw connection 49; and/or end 43 may beconnected directly to body 39, i.e. without shank 46.

Bushings 62, 63, 62 a, 63 a may be eliminated or replaced by a differenthinge position adjustment system.

The invention claimed is:
 1. A door assembly (1), in particular for ahelicopter, having a door opening (3) and comprising: a post (6); a door(8) fitted to said post by a first and second hinge (28, 27) to rotateabout a hinge axis (9) to open and close said door opening (3); saidfirst and second hinge (28, 27) being located on an outer wall (31) ofsaid post (6); said first hinge (28) comprising a fastening body (39)resting in a fixed position on said outer wall (31); and an emergencyrelease device (50) comprising a release handle (51); the door assembly(1) being characterized in that the emergency release device (50)further comprises a first stem (44), which extends through said post (6)along a release axis (45) substantially perpendicular to said hinge axis(9), rotates axially, in response to operation of said release handle(51), from a first to a second angular position to detach said door (8)from said post (6), is connected, at one axial end (43) and by areleasable connecting device (49), to said fastening body (39) of saidfirst hinge (28) in the first angular position, and is disconnected fromsaid fastening body (39) in the second angular position; in that saidrelease handle (51) is connected to said first stem (44) to rotatetogether with said first stem (44) about said release axis (45); and inthat said emergency release device (50) comprises a spring (48)pre-loaded to produce a force which tends to move said fastening body(39) axially away from said first stem (44).
 2. A door assembly asclaimed in claim 1, wherein said releasable connecting device comprisesa screw-nut screw connection (49).
 3. A door assembly as claimed inclaim 1, wherein said second hinge (27) comprises: a hinge seat (35)fixed to one (6) of said post and said door; and a hinge pin (36) whichis fixed to the other (8) of said post and said door, projects from aconnecting arm (37) along said hinge axis (9) to engage said hinge seat(35), and faces in such a direction as to allow said door (8) to dropfreely off said post (6).
 4. A door assembly as claimed in claim 1,wherein said first stem (44) is fixed along said release axis (45).
 5. Adoor assembly as claimed in claim 4, wherein said first stem (44) isconnected to said post (6) by a first positioning device (57) comprisingat least one rotary eccentric component.
 6. A door assembly as claimedin claim 5, wherein said first positioning device (57) comprises twoeccentric rotary bushings (62, 63) nested one inside the other.
 7. Adoor assembly as claimed in claim 1, comprising a further connectingdevice (34) connecting said second hinge (27) to said post (6) and inturn comprising: a second stem (44 a) fixed at one end (43 a) to asecond fastening body (29) of said second hinge (27), and extendingthrough said post (6) along a second release axis (45 a) substantiallyperpendicular to said hinge axis (9), and a second positioning device(57 a) located between said second stem (44 a) and said post (6), andcomprising at least one rotary eccentric component (62 a, 63 a).
 8. Adoor assembly as claimed in claim 7, wherein said second positioningdevice (57 a) comprises two rotary eccentric bushings (62 a, 63 a)nested one inside the other.
 9. A door assembly as claimed in claim 1,wherein said release handle (51) rotates, with respect to said firststem (44) and about a lock axis perpendicular to said release axis (45),between an extracted position and a lowered position; and by comprisinga retaining device (55) which only prevents rotation into said secondangular position when said release handle (51) is in said loweredposition.